--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx DRM bridge driver
+ *
+ * Copyright (C) 2017 Xilinx, Inc.
+ *
+ * Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <drm/drmP.h>
+
+#include <linux/list.h>
+
+#include "xlnx_bridge.h"
+#include "xlnx_drv.h"
+
+/*
+ * Overview
+ * --------
+ *
+ * Similar to drm bridge, but this can be used by any DRM driver. There
+ * is no limitation to be used by non DRM drivers as well. No complex topology
+ * is modeled, thus it's assumed that the Xilinx bridge device is directly
+ * attached to client. The client should call Xilinx bridge functions explicitly
+ * where it's needed, as opposed to drm bridge functions which are called
+ * implicitly by DRM core.
+ * One Xlnx bridge can be owned by one driver at a time.
+ */
+
+/**
+ * struct xlnx_bridge_helper - Xilinx bridge helper
+ * @xlnx_bridges: list of Xilinx bridges
+ * @lock: lock to protect @xlnx_crtcs
+ * @refcnt: reference count
+ * @error: flag if in error state
+ */
+struct xlnx_bridge_helper {
+ struct list_head xlnx_bridges;
+ struct mutex lock; /* lock for @xlnx_bridges */
+ unsigned int refcnt;
+ bool error;
+};
+
+static struct xlnx_bridge_helper helper;
+
+/*
+ * Client functions
+ */
+
+/**
+ * xlnx_bridge_enable - Enable the bridge
+ * @bridge: bridge to enable
+ *
+ * Enable bridge.
+ *
+ * Return: 0 on success. -ENOENT if no callback, -EFAULT in error state,
+ * or return code from callback.
+ */
+int xlnx_bridge_enable(struct xlnx_bridge *bridge)
+{
+ if (!bridge)
+ return 0;
+
+ if (helper.error)
+ return -EFAULT;
+
+ if (bridge->enable)
+ return bridge->enable(bridge);
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL(xlnx_bridge_enable);
+
+/**
+ * xlnx_bridge_disable - Disable the bridge
+ * @bridge: bridge to disable
+ *
+ * Disable bridge.
+ */
+void xlnx_bridge_disable(struct xlnx_bridge *bridge)
+{
+ if (!bridge)
+ return;
+
+ if (helper.error)
+ return;
+
+ if (bridge->disable)
+ bridge->disable(bridge);
+}
+EXPORT_SYMBOL(xlnx_bridge_disable);
+
+/**
+ * xlnx_bridge_set_input - Set the input of @bridge
+ * @bridge: bridge to set
+ * @width: width
+ * @height: height
+ * @bus_fmt: bus format (ex, MEDIA_BUS_FMT_*);
+ *
+ * Set the bridge input with height / width / format.
+ *
+ * Return: 0 on success. -ENOENT if no callback, -EFAULT if in error state,
+ * or return code from callback.
+ */
+int xlnx_bridge_set_input(struct xlnx_bridge *bridge,
+ u32 width, u32 height, u32 bus_fmt)
+{
+ if (!bridge)
+ return 0;
+
+ if (helper.error)
+ return -EFAULT;
+
+ if (bridge->set_input)
+ return bridge->set_input(bridge, width, height, bus_fmt);
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL(xlnx_bridge_set_input);
+
+/**
+ * xlnx_bridge_get_input_fmts - Get the supported input formats
+ * @bridge: bridge to set
+ * @fmts: pointer to formats
+ * @count: pointer to format count
+ *
+ * Get the list of supported input bus formats.
+ *
+ * Return: 0 on success. -ENOENT if no callback, -EFAULT if in error state,
+ * or return code from callback.
+ */
+int xlnx_bridge_get_input_fmts(struct xlnx_bridge *bridge,
+ const u32 **fmts, u32 *count)
+{
+ if (!bridge)
+ return 0;
+
+ if (helper.error)
+ return -EFAULT;
+
+ if (bridge->get_input_fmts)
+ return bridge->get_input_fmts(bridge, fmts, count);
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL(xlnx_bridge_get_input_fmts);
+
+/**
+ * of_xlnx_bridge_get - Get the corresponding Xlnx bridge instance
+ * @bridge_np: The device node of the bridge device
+ *
+ * The function walks through the Xlnx bridge list of @drm, and return
+ * if any registered bridge matches the device node. The returned
+ * bridge will not be accesible by others.
+ *
+ * Return: the matching Xlnx bridge instance, or NULL
+ */
+struct xlnx_bridge *of_xlnx_bridge_get(struct device_node *bridge_np)
+{
+ struct xlnx_bridge *found = NULL;
+ struct xlnx_bridge *bridge;
+
+ if (helper.error)
+ return NULL;
+
+ mutex_lock(&helper.lock);
+ list_for_each_entry(bridge, &helper.xlnx_bridges, list) {
+ if (bridge->of_node == bridge_np && !bridge->owned) {
+ found = bridge;
+ bridge->owned = true;
+ break;
+ }
+ }
+ mutex_unlock(&helper.lock);
+
+ return found;
+}
+EXPORT_SYMBOL_GPL(of_xlnx_bridge_get);
+
+/**
+ * of_xlnx_bridge_put - Put the Xlnx bridge instance
+ * @bridge: Xlnx bridge instance to release
+ *
+ * Return the @bridge. After this, the bridge will be available for
+ * other drivers to use.
+ */
+void of_xlnx_bridge_put(struct xlnx_bridge *bridge)
+{
+ if (WARN_ON(helper.error))
+ return;
+
+ mutex_lock(&helper.lock);
+ WARN_ON(!bridge->owned);
+ bridge->owned = false;
+ mutex_unlock(&helper.lock);
+}
+EXPORT_SYMBOL_GPL(of_xlnx_bridge_put);
+
+/*
+ * Provider functions
+ */
+
+/**
+ * xlnx_bridge_register - Register the bridge instance
+ * @bridge: Xlnx bridge instance to register
+ *
+ * Register @bridge to be available for clients.
+ *
+ * Return: 0 on success. -EPROBE_DEFER if helper is not initialized, or
+ * -EFAULT if in error state.
+ */
+int xlnx_bridge_register(struct xlnx_bridge *bridge)
+{
+ if (!helper.refcnt)
+ return -EPROBE_DEFER;
+
+ if (helper.error)
+ return -EFAULT;
+
+ mutex_lock(&helper.lock);
+ WARN_ON(!bridge->of_node);
+ bridge->owned = false;
+ list_add_tail(&bridge->list, &helper.xlnx_bridges);
+ mutex_unlock(&helper.lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xlnx_bridge_register);
+
+/**
+ * xlnx_bridge_unregister - Unregister the bridge instance
+ * @bridge: Xlnx bridge instance to unregister
+ *
+ * Unregister @bridge. The bridge shouldn't be owned by any client
+ * at this point.
+ */
+void xlnx_bridge_unregister(struct xlnx_bridge *bridge)
+{
+ if (helper.error)
+ return;
+
+ mutex_lock(&helper.lock);
+ WARN_ON(bridge->owned);
+ list_del(&bridge->list);
+ mutex_unlock(&helper.lock);
+}
+EXPORT_SYMBOL_GPL(xlnx_bridge_unregister);
+
+/*
+ * Internal functions: used by Xlnx DRM
+ */
+
+/**
+ * xlnx_bridge_helper_init - Initialize the bridge helper
+ * @void: No arg
+ *
+ * Initialize the bridge helper or increment the reference count
+ * if already initialized.
+ *
+ * Return: 0 on success, or -EFAULT if in error state.
+ */
+int xlnx_bridge_helper_init(void)
+{
+ if (helper.refcnt++ > 0) {
+ if (helper.error)
+ return -EFAULT;
+ return 0;
+ }
+
+ INIT_LIST_HEAD(&helper.xlnx_bridges);
+ mutex_init(&helper.lock);
+ helper.error = false;
+
+ return 0;
+}
+
+/**
+ * xlnx_bridge_helper_fini - Release the bridge helper
+ *
+ * Clean up or decrement the reference of the bridge helper.
+ */
+void xlnx_bridge_helper_fini(void)
+{
+ if (--helper.refcnt > 0)
+ return;
+
+ xlnx_bridge_debugfs_fini();
+
+ if (WARN_ON(!list_empty(&helper.xlnx_bridges))) {
+ helper.error = true;
+ pr_err("any further xlnx bridge call will fail\n");
+ }
+
+ mutex_destroy(&helper.lock);
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx DRM bridge header
+ *
+ * Copyright (C) 2017 Xilinx, Inc.
+ *
+ * Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _XLNX_BRIDGE_H_
+#define _XLNX_BRIDGE_H_
+
+/**
+ * struct xlnx_bridge - Xilinx bridge device
+ * @list: list node for Xilinx bridge device list
+ * @of_node: OF node for the bridge
+ * @owned: flag if the bridge is owned
+ * @enable: callback to enable the bridge
+ * @disable: callback to disable the bridge
+ * @set_input: callback to set the input
+ * @get_input_fmts: callback to get supported input formats.
+ */
+struct xlnx_bridge {
+ struct list_head list;
+ struct device_node *of_node;
+ bool owned;
+ int (*enable)(struct xlnx_bridge *bridge);
+ void (*disable)(struct xlnx_bridge *bridge);
+ int (*set_input)(struct xlnx_bridge *bridge,
+ u32 width, u32 height, u32 bus_fmt);
+ int (*get_input_fmts)(struct xlnx_bridge *bridge,
+ const u32 **fmts, u32 *count);
+};
+
+#if IS_ENABLED(CONFIG_DRM_XLNX_BRIDGE)
+/*
+ * Helper functions: used within Xlnx DRM
+ */
+
+struct xlnx_bridge_helper;
+
+int xlnx_bridge_helper_init(void);
+void xlnx_bridge_helper_fini(void);
+
+/*
+ * Helper functions: used by client driver
+ */
+
+int xlnx_bridge_enable(struct xlnx_bridge *bridge);
+void xlnx_bridge_disable(struct xlnx_bridge *bridge);
+int xlnx_bridge_set_input(struct xlnx_bridge *bridge,
+ u32 width, u32 height, u32 bus_fmt);
+int xlnx_bridge_get_input_fmts(struct xlnx_bridge *bridge,
+ const u32 **fmts, u32 *count);
+struct xlnx_bridge *of_xlnx_bridge_get(struct device_node *bridge_np);
+void of_xlnx_bridge_put(struct xlnx_bridge *bridge);
+
+/*
+ * Bridge registration: used by bridge driver
+ */
+
+int xlnx_bridge_register(struct xlnx_bridge *bridge);
+void xlnx_bridge_unregister(struct xlnx_bridge *bridge);
+
+#else /* CONFIG_DRM_XLNX_BRIDGE */
+
+struct xlnx_bridge_helper;
+
+int xlnx_bridge_helper_init(void)
+{
+ return 0;
+}
+
+void xlnx_bridge_helper_fini(void)
+{
+}
+
+int xlnx_bridge_enable(struct xlnx_bridge *bridge)
+{
+ if (bridge)
+ return -ENODEV;
+ return 0;
+}
+
+void xlnx_bridge_disable(struct xlnx_bridge *bridge)
+{
+}
+
+int xlnx_bridge_set_input(struct xlnx_bridge *bridge,
+ u32 width, u32 height, u32 bus_fmt)
+{
+ if (bridge)
+ return -ENODEV;
+ return 0;
+}
+
+int xlnx_bridge_get_input_fmts(struct xlnx_bridge *bridge,
+ const u32 **fmts, u32 *count)
+{
+ if (bridge)
+ return -ENODEV;
+ return 0;
+}
+
+struct xlnx_bridge *of_xlnx_bridge_get(struct device_node *bridge_np)
+{
+ return NULL;
+}
+
+void of_xlnx_bridge_put(struct xlnx_bridge *bridge)
+{
+}
+
+void xlnx_bridge_register(struct xlnx_bridge *bridge)
+{
+}
+
+void xlnx_bridge_unregister(struct xlnx_bridge *bridge)
+{
+}
+
+#endif /* CONFIG_DRM_XLNX_BRIDGE */
+
+#endif /* _XLNX_BRIDGE_H_ */
projects / zynq / linux.git / commitdiff